It’s an honor to be invited to fill in for Olivia. We’ll be writing about slow and fast forces that shape the brain: natural selection, operating relatively slowly over many generations; and environmental influences, whose effects are visible across a few generations or even within one individual’s lifetime.

We’re often asked whether the human brain is still evolving. Taken at face value, it sounds like a silly question. People are animals, so selection pressure would presumably continue to apply across generations.

But the questioners are really concerned about a larger issue: how our brains are changing over time — and whether we have any control over these developments. This week we discuss intelligence and the “Flynn effect,” a phenomenon that is too rapid to be explained by natural selection.

It used to be believed that people had a level of general intelligence with which they were born that was unaffected by environment and stayed the same, more or less, throughout life. But now it’s known that environmental influences are large enough to have considerable effects on intelligence, perhaps even during your own lifetime.

A key contribution to this subject comes from James Flynn, a moral philosopher who has turned to social science and statistical analysis to explore his ideas about humane ideals. Flynn’s work usually pops up in the news in the context of race issues, especially public debates about the causes of racial differences in performance on intelligence tests. We won’t spend time on the topic of race, but the psychologist Dick Nisbett has written an excellent article on the subject.

Flynn first noted that standardized intelligence quotient (I.Q.) scores were rising by three points per decade in many countries, and even faster in some countries like the Netherlands and Israel. For instance, in verbal and performance I.Q., an average Dutch 14-year-old in 1982 scored 20 points higher than the average person of the same age in his parents’ generation in 1952. These I.Q. increases over a single generation suggest that the environmental conditions for developing brains have become more favorable in some way.

What might be changing? One strong candidate is working memory, defined as the ability to hold information in mind while manipulating it to achieve a cognitive goal. Examples include remembering a clause while figuring out how it relates the rest of a sentence, or keeping track of the solutions you’ve already tried while solving a puzzle. Flynn has pointed out that modern times have increasingly rewarded complex and abstract reasoning. Differences in working memory capacity account for 50 to 70 percent of individual differences in fluid intelligence (abstract reasoning ability) in various meta-analyses, suggesting that it is one of the major building blocks of I.Q. (Ackerman et al; Kane et al; Süss et al.) This idea is intriguing because working memory can be improved by training.

Felix Sockwell

A common way to measure working memory is called the “n-back” task. Presented with a sequential series of items, the person taking the test has to report when the current item is identical to the item that was presented a certain number (n) of items ago in the series. For example, the test taker might see a sequence of letters like

L K L R K H H N T T N X

presented one at a time. If the test is an easy 1-back task, she should press a button when she sees the second H and the second T. For a 3-back task, the right answers are K and N, since they are identical to items three places before them in the list. Most people find the 3-back condition to be challenging.

A recent paper reported that training on a particularly fiendish version of the n-back task improves I.Q. scores. Instead of seeing a single series of items like the one above, test-takers saw two different sequences, one of single letters and one of spatial locations. They had to report n-back repetitions of both letters and locations, a task that required them to simultaneously keep track of both sequences. As the trainees got better, n was increased to make the task harder. If their performance dropped, the task was made easier until they recovered.

Each day, test-takers trained for 25 minutes. On the first day, the average participant could handle the 3-back condition. By the 19th day, average performance reached the 5-back level, and participants showed a four-point gain in their I.Q. scores.

The I.Q. improvement was larger in people who’d had more days of practice, suggesting that the effect was a direct result of training. People benefited across the board, regardless of their starting levels of working memory or I.Q. scores (though the results hint that those with lower I.Q.s may have shown larger gains). Simply practicing an I.Q. test can lead to some improvement on the test, but control subjects who took the same two I.Q. tests without training improved only slightly. Also, increasing I.Q. scores by practice doesn’t necessarily increase other measures of reasoning ability (Ackerman, 1987).

Since the gains accumulated over a period of weeks, training is likely to have drawn upon brain mechanisms for learning that can potentially outlast the training. But this is not certain. If continual practice is necessary to maintain I.Q. gains, then this finding looks like a laboratory curiosity. But if the gains last for months (or longer), working memory training may become as popular as — and more effective than — games like sudoku among people who worry about maintaining their cognitive abilities.

Now, some caveats. The results, though tantalizing, are not perfect. It would have been better to give the control group some other training not related to working memory, to show that the hard work of training did not simply motivate the experimental group to try harder on the second I.Q. test. The researchers did not test whether working memory training improved problem-solving tasks of the type that might occur in real life. Finally, they did not explore how much improvement would be seen with further training.

Research on working memory training, as well as Flynn’s original observations, raise the possibility that the fast-paced modern world, despite its annoyances (or even because of them) may be improving our reasoning ability. Maybe even multitasking — not the most efficient way to work — is good for your brain because of the mental challenge. Something to think about when you’re contemplating retirement on a deserted island.

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Clarification: We wrote that in the complex version of the n-back task, test-takers “saw” two sequences of stimuli. In fact, the letter sequence was heard. Thanks to commenter Adam Thomas for pointing this out.

The Flynn effect is interesting, and no doubt something real is going on there. But heredity still matters, and I would really like to see someone writing in a mainstream publication like the Times address something that looks like it might be problem: the fact (if indeed it is a fact – that’s one of the things that needs to be addressed!) that intelligent people tend to marry later and have fewer children than people who are less intelligent. Unless you believe that human intelligence is special, and not subject to evolution, it’s hard to avoid the conclusion that we are breeding intelligence out of our population, the only question being how fast. The Flynn effect can’t save us here. Whatever the Flynn effect is, it is not genetic, and sustained reproductive selection for low intelligence must eventually overwhelm it.

So, is this something you will be talking about at some point? Or is it too off limits? (Are you even allowed to acknowledge that it’s off limits, or is that off limits too?)

“People are animals, so selection pressure would presumably continue to apply across generations.”

Huh? What selection pressures?

Natural selection is based on reproduction, and last I checked, the dumb were reproducing just fine and, ceteris paribus, more prolifically than the non-dumb.

Your argument makes some sense up until the advent of computers and the bureacratization of private enterprise. Now 95% of the jobs out there require endless mindless numbing repetition. I have a very hard time believing that anyone working in, say, an HR department would be increasing their IQ, even if their working memory is improving by repeatedly practicing the simple task of, matching skill sets, checking boxes, and so on.

Personally, I went from a white-shoe law firm practicing international trade law to living on that desert island, and the variety of stimuli I get here, between the coconuts and writing, is far higher than I ever got as a glorified secretary reading 500-page addenda on ball-bearing classifications (i.e., first-year associate).

A large component of an IQ test simply tests working memory. So improving one’s working memory improves one’s IQ as measured by the test. But that doesn’t mean we’re actually getting smarter, just that the IQ test itself is getting skewed away from measuring actual fluid intelligence.

The idea that intelligence isn’t fixed, and can be increased by environment and training, is not new. Here is some information on Feuerstein:

Professor Reuven Feuerstein (born August 21, 1921 in Botoşani, Romania) (hebrewפוירשטיין) is a Israeli medical doctor of the originator of the theory of Structural Cognitive Modifiability (SCM), the theory of Mediated Learning Experience (MLE), and Feuerstein Instrumental Enrichment (FIE). The idea that intelligence can be taught is at the core of Prof. Feuerstein’s work.

Feuerstein studied at the University of Geneva under Jean Piaget, Andre Rey, Barbel Inhelder, and Marguerite Loosli Uster and is a peer of Lev Vygotsky. He is the chairman of the International Center for Enhancement of Learning Potential (ICELP) in Jerusalem. The concepts that intelligence is plastic and changeable, not fixed, and that intelligence can be “taught” are central to the theory of Structural Cognitive Modifiability. Intelligence can be developed within a mediated learning environment created with the theory of Mediated Learning Experience. A mediator is a person who works in relationship with the learner in developing cognitive functions leading to clearer thinking and improved learning processes.

After developing these theories and a set of practices for mediation to enhance the thinking of child survivors of the Holocaust, Feuerstein uncovered teacher’s needs for methods that would ground their work in a curriculum format. To this end, he developed 14 “instruments” that mediators and students use to enrich cognitive functions and to build habits of efficient thinking. He organized these “content free” instruments into a single three-year program for students above the age of 9 known as Feuerstein Instrumental Enrichment.

After 50 years of success, documented by over 1500 scientific research studies with various populations including engineers at a Motorola (USA) plant, impoverished students in rural communities (Bahia, Brazil), non-literate immigrants (Ethiopia), Autistic and Down Syndrome children (Jerusalem), low-performing high school math students (Cleveland, Ohio, USA), weak readers in middle grades (Portland, Oregon, USA), and many other groups. Feuerstein developed a BASIC version of Instrumental Enrichment for use with early childhood and severely challenged adolescents. Projects throughout the State of Alaska (USA) and in Britain, Italy, India and Japan are exploring the applications of the new instruments with young children especially as a way to avoid the over-categorization of students as learning disabled.

My experience with Feuerstein’s methods involved an exercise connecting dots to form a square and two triangles. Each set of dots was more complex than the previous set.

Key to the exercise, was forming strategies and techniques for finding the square and triangles. In a mediated session, the student is asked by the mediator to explain what methods the student used in solving each dot pattern. By explaining the way they solved the puzzle, the student reinforced the though processes they used.

The fundamental flaw in most of the studies is that there is no objective determinant of race. There are no absolute exclusive genetic markers for any one race. In most of the IQ tests and other experiments, people were asked to self identify their race or the examiners arbitrarily assigned race.

Without objective measures of what are the precise characteristics of any particular race, the studies are dubious at best to answer any meaningful questions or help society
respond in allocating its resources equitably.

Interesting, though I would predict the generational gains are more about nutrition than anything else. Although it’s possible that selective pressure is partly at issue (perhaps smarter people avoid death in war, or there is more sexual selection for intelligence today in certain societies).

I imagine n-back websites are going to spring up within hours, followed by n-back banner ads…

Interesting stuff. Kindly refer us to the software so we can practice for ourselves.

Also, are you aware of research that daily consumption of colloidal gold (10 PPM gold in water) can increase IQ by as much as 20%? Two published European studies suggest this. (Sorry, I don’t have the references handy.)

Almost everyone can increase their intelligence; the point is whether anyone can increase their potential for intelligence. I do not believe so, and nothing that I have read or seen to date convinces me otherwise.

Increasing I.Q. scores is more of a scam than of a fact. What is I.Q.?

When you know the numbers that supposedely define your level of intelligence, does that make you more inteliigent, or do you merely think that you are intelligemt?

When I was a soldier well into my first tour of duty, a Company Clerk asked me whether I had ever read my scores.

I replied that those scores that were hand-carried with other orders in a packet that was sealed were required to remain sealed. He laughed at that bit of naivete and told me that at that stage in my career everyone had looked at their orders and that they knew their I.Q. scores that were derived from their initial Battery Tests Scoring over four days of testing before entering Boot Camp[.

He told me that mine were the third highest in the Company, and that only the three officers in the Company matched or were higher than mine.

He also assured me that the Company Commander and the First Sergeant were well aware of my I.Q. results..

I never knew them before that point, and they never influenced my thinking after that point. I considered them numbers.

There were senior NCOs in that Company who had fought in WWII and Korea, that is, 8 years of combat.

I would never presume to know more than those leaders, or to presume that I ever would know more.

Sergeant’s Majors were required then to have at least 2 years of college, and to finish 4 years of college. Today, SGTs Majors must have 4 years of college before promotion, and in some cases must have Master’s degrees as they continue in that rank.

Sergeant Major’s go up to Command Sergeants Major in Battalion, Regiment, Brigade, Divisional, Corps and Army levels. They had better know what they are doing at those lofty heights.

When I measured my scores against those men who have also served in combat, my numbers are meaningless.

Is it working memory or pattern recognition ? My work with children and intellectual disability leads me to believe it is the inability to generalise letter patterns that makes reading, a mainly visual operation a difficult task for these children.

Studies like these are interesting, but why are there so few compatible studies questioning the point of this kind of learning? I have 2 examples from experience that lead me to question whether the kind of ‘intelligence’ measured by the IQ is useful in any way.

First is from where I often teach in South Korea. The students there (to make a broad generalization) are much stronger than I am in this kind of test-taking. If we sat down together for a math test, a sudoku game or an IQ test, I have no doubt that many of my students would score higher than I would. At the same time, I’d hesitate to recommend _any_ of these students to the highest American universities (at least, not without serious caveats). The issues are somewhat complicated by culture and bias, but the basic problem is that these students cannot use what they learn in what seems to me like a meaningful way. They simply cannot think critically. The fault doesn’t lie with the students’ innate abilities but clearly derives from their educational background. Without the ability to reason critically, no ability to reason quickly is of much use. So I fail to see how this is an improvement in ‘intelligence.’

The second example is just a short observation in how trendy Eastern religions/philosophies have become in the West over the past 50-100 years. I think there’s something people recognize about sitting there, trying to think nothing, that appears at least _as_ valuable as being able to process puzzles super quick. It seems to me that most people recognize in this something of ‘wisdom’ vs what this article describes as ‘intelligence.’ It would be nice to know if one is being supplanted by the other, if (to take an extreme view) the perceived rise in the number of autism cases isn’t just one example of overly rewarding the reasoning parts of our brains at the expense of a more holistic view (one in which we also learn to _choose_ and to _forget_).

perhaps they should do more testing on the IQ tests before using them as a measure or proxy of intelligence. It is a major oversight that the author failed to even discuss how the dramatic 20-point change in average IQ scores of the course of 1 generation significantly erode the reliability and validity of the test itself. 20 points is the difference between average intelligence and borderline mental retardation. Clearly there are some significant questions about the intelligence testing that need to be addressed before we use them as proxies for intelligence.

Is there any data on actors, who have to remember their lines—entire plays if they’re in the theatre, a great deal of new text daily if they’re working in television, especially, gasp, in soap opera? Likewise, classical musicians, who must remember an entire repertoire of long pieces. I wonder what the data might be on that. Are our soap opera actors among the most intelligent people around by now? If so, they are better actors than we tend to think they are, because all that intelligence does not show.

But this is wrong and smacks of left wing political pandering. First off, IQ, a measure of individual intelligence is real. I’ve seen it my whole life and see it now in my children and employees. The writers here ponder why IQ scores have gone up over time but it doesn’t seem to occur to them that IQ tests are very, very imperfect. For myself I’ve been judged to have an IQ of alternatively between 135 and 150 but I take that with a truckload of salt. Intelligence, per se, isn’t what gets one ahead in life. Personality, ambition and emotion matter just as much if not more. And exactly what is intelligence? Well guess what, it’s a highly subjective question and will remain an endless argument and political talking point.

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Olivia Judson, an evolutionary biologist, writes every Wednesday about the influence of science and biology on modern life. She is the author of “Dr. Tatiana’s Sex Advice to All Creation: The Definitive Guide to the Evolutionary Biology of Sex.” Ms. Judson has been a reporter for The Economist and has written for a number of other publications, including Nature, The Financial Times, The Atlantic and Natural History. She is a research fellow in biology at Imperial College London.